161780636 has 24 divisors (see below), whose sum is σ = 300409200. Its totient is φ = 75969792.

The previous prime is 161780609. The next prime is 161780657. The reversal of 161780636 is 636087161.

It is a self number, because there is not a number n which added to its sum of digits gives 161780636.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33290 + ... + 37838.

It is an arithmetic number, because the mean of its divisors is an integer number (12517050).

Almost surely, 2^161780636 is an apocalyptic number.

It is an amenable number.

161780636 is a deficient number, since it is larger than the sum of its proper divisors (138628564).

161780636 is a wasteful number, since it uses less digits than its factorization.

161780636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5093 (or 5091 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 161780636 is about 12719.3017103928. The cubic root of 161780636 is about 544.8900106295.

The spelling of 161780636 in words is "one hundred sixty-one million, seven hundred eighty thousand, six hundred thirty-six".